Industrial gas turbine exhaust system with modular struts and collars

An industrial gas turbine apparatus, comprising:

• a compressor section;
• a combustor section;
• a turbine section including a last downstream row of turbine blades that are mounted on a rotating shaft;
• and
• an industrial gas turbine exhaust system, having:
• a turbine exhaust case (TEC) coupled to a downstream end of the turbine section;
• an inner case;
• an outer case circumscribing the inner case in spaced relationship relative to a centerline defined by the exhaust system;
• a turbine exhaust path defined between the outer and inner cases, extending downstream of the turbine blades;
• a plurality of struts interposed between the outer and inner cases that are tilted at an angle relative to a radius defined by the exhaust system centerline;
• and
• first and second strut collars respectively coupled to respective ends of each strut and its respective abutting outer or inner case, each respective collar outer surface having a constant fillet radius external profile on an acute angle side thereof, for smooth exhaust flow transition between its respective strut and abutting case surface, the fillet radius profile having a range of 15%-40% of strut maximum thickness, each strut collar having a cross section thickness varying by no more than 10% at any circumferential location.